I replaced the radial seal in my distributor and decided to replace the sealed ball bearing as well. Original bearing is a KOYO 6001RS. When measuring the old bearing I noticed that the inside diameter of the inner race was larger than spec for a 6001 bearing. Ordered a new KOYO 60012RSC3 bearing and it looked identical to the old one but the old bearing's ID is 12.4mm and the new one is 12mm. Measured the shaft and it is 12.44mm. I was concerned about this difference and the pressure my press was using to get it on seemed like too much for this application. Couldn't find anything online to explain why this old standard bearing had an oversized ID except that some bearings have an "interference fit" to keep the bearing in place, after pressing in. I said screw it and tried pressing it on. With an audible snap, the inner race of the bearing cracked and I found the surface of the shaft to be a bit deformed from forcing the bearing on it. Can anyone explain this f**kery?

Distributor is from a D15B JDM VTEC
Old bearing dimensions: 12.4x28x8
New bearing dimensions: 12x28x8

 

Figured it out. Distributor uses a special bearing with an inside diameter of 12.5mm. Part number 6001-012-2nsl

 

Why diddnt you just buy the original part from the dealer to begin with?

 

Because you can order a Koyo part and save some money. I've done it with tension belt bearings because it was $27 vs $79.

.017" is way too big to try and press fit. A press fit is usually around .002"

 

I would have but they don't sell the bearing by itself. They sell the entire distributor housing, which is discontinued on Majestic Honda and probably over $100 if it was available. There may be a "secret" Honda part number out there for it, like the trailing arm bushings, but if there is I can't find it.
I've always been able to order bearings directly with the numbers on them and/or measuring their dimensions. For example, the AC compressor tensioner pulley for my engine is sold as one unit, with bearing, for $45. When the bearing went bad in mine I looked up the number on it, checked dimensions with my caliper, and purchased it for less than $10; pressed it in and good to go. This distributor bearing is an odd fluke because it only says 6001RS, while the aftermarket bearing correctly sized have -012 or /012in their part number.
I had a strong feeling that the fit was too tight. I wanted to get it together so I ignored the signs and did a Hail Mary. I knew better *sigh*

 

I see.

 

because, last i've seen, they don't sell that part.

 

Just for my knowledge, what is the seal part number?

 

Original seal was made by NOK, part number on the seal is BH3888E. I purchased a distributor seal kit from Autozone made by Dorman, part number 917-136. Had the distributor o-ring and two radial seals of different sizes. The seal that fit mine was 12.5x22.5x5(mm). The other seal in the kit is 12.45x22x6(mm), which seems to be for some F series distributors.